11
The transmitters can be installed in various
positions, but the following needs to be taken into
account: For level measurement the installation
should be at the base of the tank or at the point of
minimum level measurement (fig.1). This means
that the reference point for the base measurement
will become the point at which the sensor is
installed which will not necessarily be at the
bottom of the tank.
It is advisable to install a blocking valve between
the transmitter and the connection to perform
maintenance without having to stop the process.
Avoid installing in the tank outlet or near shaker
where there is pressure pulses thus preventing
rapid changes in the signal. For this case it is
necessary the use of still-pipe (Stilling tube) to
absorb the liquid surfaces (Fig. 2).
Min.
Max.
Valve
H
e
ig
h
t
“h
”
4...20mA
Base
atm
Pressure
Principle of Operations
The weight of the column of liquid
generates hydrostatic pressure on the
diaphragm of the sensor. When the
density of the product is constant and
the quantity of the liquid is increased
or decreases, there will be a
proportional output from the sensor .
Fig.2
Fig.1
Density
Specific Gravity
Pump
Pressure of the Liquid Column
Water Column
P(mH2O)= relative density.h(m)
System MKS
P(KPa)= density(Kg/m3). g(m/s). h(m)
System MKgfs
P(Kgf/m2)= Specific Gravity(Kg/m3). h(m)
Installation
